Advances in Computer Science : an International Journal (ACSIJ)
Today, wireless LANs are growing dramatically. Most of these networks are designed and run based on the IEEE 802.11 standard. Current specification of 802.11 provides multiple transmission rates in physical layer, which are used in various modulations. In order to apply multiple rates capability, the sender must select best transmission rates dynamically at different times according to channel quality and without feedback; choose explicit information from the receiver. Such practice is called the rate adaptation.